I recommend looking up the Battle of the Chosin Resevoir....worst military defeat ever suffered by the US (worse than Bastogne imho), the Chinese didn't even have one gun per soldier...some didn't have boots...they DEMOLISHED the best equipped army in the world (and this was during Korea when the US military was the unquestioned top dog)

and btw if you are going to go look at casualty counts, don't bother, its well understood that the Chinese lost ten men for every US soldier killed...they still won